Patent Literature 1 discloses a technique for a valve device configured as above.
The technique disclosed in Patent Literature 1 is adopted in a valve device which uses a valve body having a cylindrical surface. When the valve body is rotated in a valve closing direction, the valve body closes a valve opening provided to the housing by allowing a valve-facing surface of the valve body to make contact with a housing. The valve-facing surface is a surface of the valve body facing in a rotational direction.